diff --git a/proto/src/wifi.proto b/proto/src/wifi.proto
index d68442f..2214ac5 100644
--- a/proto/src/wifi.proto
+++ b/proto/src/wifi.proto
@@ -2354,7 +2354,7 @@
   optional int32 num_request = 1;
 
   // Histogram of requests via this API surface to number of networks matched in scan results.
-  optional HistogramBucketInt32 network_match_size_histogram = 2;
+  repeated HistogramBucketInt32 network_match_size_histogram = 2;
 
   // Number of successful network connection from this API.
   optional int32 num_connect_success = 3;